Pretty Big Worm!!!! - Help identify

[wayner]

Thanks Brad, needless to say, I'll be on the hunt, when I think back now, there was a small piece of liverock that was moved awhile back, it was on the sandbed & moved 4 or 5 inches. over to where the worm retreated to on Sunday, almost set up as a blockade, when I look towards the back where he went, there are 2 snail shells.

I know I didn't move the rock, would it be capable of doing this?